Context-oriented Android Application Behavior Analysis And Presentation Technology Research

Android system uses the permission model to protect the access to sensitive resources of system.Each application needs to explicitly declare the rights it uses and ask the user whether to grant the permission when applying for the protecting method of the access rights.However,due to the coarse granularity of the Android permission model,it can not control the behavior of the permission protection method in different application contexts,so that the malicious behavior can be hidden behind the legal function of the application and is hard to be noticed.In addition,the permission description information provided by Android application is too broad,and it can not reflect the context state of permission and permission protection method when in operation state,resulting in that users can not understand the operation method and behavior of permissions.Blind grant of permission brings great security risk to users.In this thesis,in order to solve the security problems in the Android permission model,this thesis analyzes the security-sensitive behaviors related to application rights in detail and proposes a context-oriented Android application behavior analysis method to obtain the contextual information of behaviors of permission usage.Further,the runtime monitoring and representation method of Android application sensitive behavior is proposed to provide users with the context information used by the runtime permission,which helps the user to understand how the permission to be granted is to be used.On the basis of the above two methods,a context-oriented Android application behavior analysis and representation system is designed and implemented,it solves the security problem faced by the Android permission mechanism to a certain extent.The main work of this thesis is as follows:(1)This thesis studies the authority system of Android system,and through in-depth observation and analysis of the application behavior in the Android application sample,it reveals that the current Android permission mechanism has the problems of coarse granularity and user's inability to understand the runtime permission behavior.It analyzes the security threats to Android application and proposes the basic idea of using security-sensitive behavioral context to achieve Android application behavior analysis and presentation.(2)A context-oriented Android application behavior analysis method is proposed.Access to sensitive resources of Android system is usually realized by the method of rights protection system.The usage behavior of corresponding rights can be understood by getting the context information of security sensitive behavior.Therefore,starting from the method of rights protection system,this thesis combines the techniques such as component modeling and program dependency analysis and uses a guided reverse symbolic execution analysis method to generate the complete contextual information that can accurately characterize the use of authority,on this basis it realizes the description of user-understandable permission usage.(3)This thesis proposes a method of Android application sensitive behavior runtime monitoring and presentation.Android application will check the permission of system call in security-sensitive behavior when in running state and do the runtime monitoring of Android sensitive behavior.Users will be granted the ability to decide whether to grant the permission according to permission usage behavior at the permission checkpoint.By displaying the runtime behavior description information to the user,he or she can make decisions based on fully understanding the authority behavior that leads to the security improving of the Android authority mechanism.(4)Design and implement a context-oriented Android application behavior analysis and presentation system.Based on the above two methods,the system enhances the security of the Android permission mechanism.The experiment results show that the system can provide decision support for authorization process of users and can effectively implement the function of context-oriented fine-grained access control.